Some liquid mixtures are sensitive to high shear forces which may cause a disruption of droplets, particles or agglomerates of particles in the liquid mixture. For example shearing of an emulsion of two immiscible liquids such as oil and water reduces drop sizes and makes separation more difficult. It may therefore be an object to provide gentle acceleration of the liquid mixture when entering into the rotor of the separator, rotating at high speed.
An example of a centrifugal separator having an inlet which is gentle to the liquid mixture of components is disclosed in EP 0225707 B1. This document discloses a centrifugal separator provided with an inlet arrangement in the form of a set of annular discs arranged coaxially with the rotor and forming passages for liquid between them.
Another example of a centrifugal separator having an inlet which is gentle to the liquid mixture of components is disclosed in EP 1105219 B1. This document discloses a centrifugal separator provided with an inlet arrangement in the form of a helically shaped element extending along the inlet pipe, forming passages for liquid between adjacent windings of the element.
A further example of a centrifugal accelerator is disclosed in WO 91/12082, in which the inlet comprises a smooth baffle disc and a number of entraining discs for gently entraining a supplied liquid.
However, in some applications, an inlet arrangement as disclosed in prior art may cause an internal overflow within the centrifugal separator, in particular at high inlet flow. Upon such conditions, the unseparated liquid mixture may overflow into the outlet for separated liquid, thereby impairing the separation quality.